Part 15 (2/2)
Thus commencing our investigations by a careful survey of any one bone by itself, a person who is sufficiently master of the laws of organic structure may, as it were, reconstruct the whole animal to which that bone had belonged.”
After applying the same principle to animals with hoofs, Cuvier comes to a conclusion even more surprising. ”Hence,” says he, ”any one who observes merely the print of a cloven hoof, may conclude that it has been left by a ruminant animal, and regard the conclusion as equally certain with any other in physics or in morals. Consequently this single footmark clearly indicates to the observer the forms of the teeth, of all the leg bones, thighs, shoulders, and of the trunk of the body of the animal which left the mark. It is much surer than all the marks of Zadig.
”By thus employing the method of observation, where theory is no longer able to direct our views, we procure astonis.h.i.+ng, results. The smallest fragment of bone, even the most apparently insignificant apophysis, possesses a fixed and determinate character relative to the cla.s.s, order, genus, and species of the animal to which it belonged; insomuch that when we find merely the extremity of a well-preserved bone, we are able, by a careful examination, a.s.sisted by a.n.a.logy and exact comparison, to determine the species to which it once belonged, as certainly as if we had the entire animal before us. Before venturing to put entire confidence in this method of investigation, in regard to fossil bones, I have very frequently tried it with portions of bones belonging to well-known animals, and always with such complete success, that I now entertain no doubts with regard to the results which it affords.”
The remarkable correlation between the parts of existing animals having been thus proved by the most rigid and satisfactory tests, we shall inquire with interest for the result, when Cuvier applied the same principles to the fossil animals. If the laws of anatomical structure were the same when these extinct races lived as they now are, these principles will apply equally well to the bones found in the rocks; and though often only scattered fragments are brought to light, the anatomist will be able to reconstruct the whole animal, and present him to our view. Cuvier was the first who solved this problem. The quarries around Paris had furnished a vast number of bones of strange animals, and these were thrown promiscuously into the collections of that city. Well prepared by previous study, this distinguished anatomist went among them with the inquiry, _Can these bones live?_ The spirit of scientific prophecy was upon him, and, as he uttered his inspirations, _there was a noise, and behold a shaking, and the bones came together, bone to his bone. And the sinews and the flesh came upon them, and the skin covered them._ ”I found myself,” says he, ”as if placed in a charnel-house, surrounded by mutilated fragments of many hundred skeletons of more than twenty kinds of animals, piled confusedly around me. The task a.s.signed me was to restore them all to their original position. At the voice of comparative anatomy, every bone and fragment of a bone resumed its place. I cannot find words to express the pleasure I experienced in seeing, as I discovered one character, how all the consequences which I predicted from it were successively confirmed; the feet were found in accordance with the characters announced by the teeth; the teeth in harmony with those indicated beforehand by the feet; the bones of the legs and thighs, and every connecting portion of the extremities, were found set together precisely as I had arranged them, before my conjectures were verified by the discovery of the parts entire; in short, each species was, as it were, reconstructed from a single one of its component elements.”
It is hardly necessary to say that, since this first successful experiment, the same principles have been more thoroughly investigated and extended with the same success into every department of fossil organic nature. The results which have crowned the labors of such men as Aga.s.siz, Ehrenberg, Kaup, Goldfuss, Bronn, Blainville, Brongniart, Deshayes, and D'Orbigny, on the continent of Europe, and of Conybeare, Buckland, Mantell, Lindley, and Hutton, and eminently of Owen, in Great Britain, although sustained by the most rigid principles of science, are nevertheless but little short of miraculous; and they demonstrate most clearly the ident.i.ty of anatomical laws, in all ages, among animals and plants of every size and character, from the lofty lepidodendra and sigillaria to the humblest moss or sea-weed, and from the gigantic dinotherium, mastodon, megatherium, and iguanodon, to the infinitesimal infusoria.
_In the sixth place, physiological laws have always been the same upon the globe._
That death has reigned in all past ages over all animated tribes, as it now reigns, so that in that war there has never been a discharge, I need not attempt formally to prove. For the preserved and petrified relics of all the former races, that now lie entombed in the rocks, furnish a silent but impressive demonstration of the former triumph of that great physiological law, which is stamped by the signet of Jehovah upon all existing organic natures--_Dust thou art, and unto dust shalt thou return._
Scarcely more necessary is it to attempt to show that the same system of reproduction for filling the chasms which death occasions, and which is now universal in the animal and vegetable kingdoms, has always existed.
Indeed, such a system is a necessary counterpart to a system of dissolution. And we find the same phases to this reproductive system in ancient and in modern periods. Organic remains clearly teach us that there have always been viviparous as well as oviparous creatures, and gemmiparous as well as fissiparous animals and plants. The second great physiological law of existing nature has, then, always been the same.
The character of the nourishment by which animals and plants have been sustained has never varied. The latter have ever been nourished by inorganic, and the former by organic, matter. Some animals have ever fed upon the flesh of other animals, as their petrified remains, enclosing the masticated and half-digested fragments of other animals, testify. Other tribes have fed only upon herbs or fruits; and some were omnivorous; just, in fact, as we find the habits of existing animals.
No less certain are we that the processes of digestion and a.s.similation have ever been unchanged. We find the same organs for these purposes as in existing animals, viz., the mouth, the stomach, the intestines, and the blood-vessels, as the coprolites and the cololites abundantly testify. We infer, therefore, with great confidence, the existence of gastric juice and bile for completing the transformation of the food into blood. Indeed, the discovery by a lady (Miss Mary Anning, of England) of that singular secretion from which the color called _India ink_ is prepared, with the ink-bag of the sepia, or loligo, in a petrified state, shows that the process of secretion existed in these ancient animals; and when we find that in all respects their structure was like that of existing animals, although some of the softer vessels have not been preserved, we cannot doubt but the entire process of digestion, and the conversion of blood into bone, nerve, and muscle, was precisely the same as it now is.
In the fact, also, that we find in fossil specimens organs of respiration, such as lungs, gills, and trachea, we learn that the process of a circulation of blood, and its purification by means of the oxygen of the atmosphere, have never varied. Animal heat, too, dependent as it is essentially upon this oxygenating process, was always derived from the same source as at present.
The perfectly preserved minute vessels of vegetables enable us, by means of the microscope, to identify them with the plants now alive; and they prove, too, incontestably, that the nourishment of vegetables has always been of the same kind, and has been converted into the various proximate principles of plants by the same processes.
Again. We have evidence that these ancient animals possessed the same senses as their congeneric races now on the globe. We have one good example in which that most delicate organ, the eye, is most perfectly preserved. It is well known that the visual organ of insects and of crustaceans is composed of a mult.i.tude--often several hundreds or thousands--of eyes, united into one, so as to serve the purpose of a multiplying gla.s.s; each eye producing a separate image of the object observed. Such an eye had the trilobite. Each contained at least four hundred nearly spherical lenses on the surface of the cornea, united into one organ; revealing to us the interesting fact, that the relations of light to animal organization were the same in that remote era as they now are.
But I need not multiply proof of the functional ident.i.ty of organic nature in all ages. It may, however, be inquired, how this ident.i.ty, as well as that of anatomical structure, is reconciled with the great anomalies, both in size and form, which have confessedly prevailed among ancient animals.
Compare the plants and animals which now occupy the northern parts of the globe with those which flourished there in the remote periods of geological history, and can we believe them to be portions of one great system of organic nature?
Compare, for instance, the thirty or forty species of ferns now growing to the height of a few inches, or one or two feet, in Europe and this country, with the more than two hundred species already dug out of the coal mines, many of which were forty to forty-five feet in height; or the diminutive ground pines, and equiseta, now scarcely noticed in our forests, with the gigantic lepidodendron, sigillaria, calamites, and equiseta, of the carboniferous period; and who will not be struck with the great difference between them?
Or go to Germany, and imagine the bones of the dinotherium to start out of the soil, and become clothed with flesh and instinct with life. You have before you a quadruped eighteen feet in length, and of proportional height, much larger than the elephant, and with curved tusks reaching two or three feet below its lower jaw, while no other living animal would be found there larger than the ox, or the horse--mere pygmies by the side of such a monster, and evidently unfit to be his contemporaries.
Again. Let the megatherium be brought back to life on the pampas of South America, and you have an animal twelve feet long and eight feet high, with proportions perfectly colossal. Its fore feet were a yard long, its thigh bone three times thicker than that of the elephant, its width across the haunches five feet, its spinal marrow a foot in diameter, and its tail, where it was inserted into the body, two feet in diameter. What a giant in comparison with the sloth, the anteater, and the armadillo, to which it was allied by anatomical structure!
Still more unequal in size, as compared with living batrachians, was the labyrinthidon, once common in England and Germany, if, indeed, the tracks on sandstone were made by that animal. It was, in fact, a frog as large as an ox, and perhaps as large as an elephant. Think of such animals swarming in our mora.s.ses at the present day!
But coming back from Europe, and turning our thoughts to the animals that trod along the sh.o.r.es of the estuary that once washed the base of Mount Holyoke, in New England, we shall encounter an animal, probably of the batrachian family, of more gigantic proportions. It was the _Otozoum Moodii_, a biped, with feet twenty inches long, more than twice the size of those of the labyrinthidon; yet its tracks on the imperishable sandstone show that such a giant once trod upon the muddy sh.o.r.e of that ancient estuary.
Along that same sh.o.r.e, also, enormous struthious birds moved in flocks, making strides from three to five feet long, with feet eighteen inches long, lifting their heads, it may be, from twelve to eighteen feet above the ground, surpa.s.sing, as it appears, even the gigantic dinornis of New Zealand, now that the feet of the latter have been discovered. I refer to the _Brontozoum giganteum_, whose tracks are so common on the new red sandstone of the Connecticut valley. What dwarfs are we in comparison, who now consider ourselves lords of that valley!
Still more remarkable for peculiarities of structure was the tribe of saurians, which were once so numerous in the northern parts of Europe and America. The ichthyosaurus, a carnivorous marine reptile, sometimes thirty feet long, had the snout of a porpoise, the teeth of a crocodile, the head of a lizard, the vertebr of a fish, the sternum of an ornithorhynchus, and the paddles of a whale. Those paddles, corresponding to the fins of a fish, or the web feet of water birds, were composed, each of them, of more than one hundred bones. In short, we find in this animal a combination of mechanical contrivances, which are now found among three distinct cla.s.ses of the animal kingdom. Its eye, also, having an orbital cavity, in one species, of fourteen inches in its longest diameter, was proportionally larger than that of any living animal.
The plesiosaurus had the general structure of the ichthyosaurus; but its neck was nearly as long as its whole body--longer, in proportion to its size, than even that of the swan.
The iguanodon was an herbivorous terrestrial reptile that formerly inhabited England. It approaches nearest in structure to the iguana, a reptile four or five feet long, inhabiting the marine parts of this continent. Yet the iguanodon was thirty feet long, with a thigh six feet, and a body fourteen feet in circ.u.mference. What an alarm would it now produce, to have such a monster start into life in the forests of England, where no a.n.a.logous animal could be found more than half a foot in length!
Surely this must have been one of the fabulous monsters of antiquity.
<script>